SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575814f51778b043cb7841700eff23858c066757d786205f4571229da9972d08' 
  AND token = 'W9XNLyBpq2nVNPIqDZjQfNIqO/QzG8RsW9vApPTTyAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}